Time delay mechanism



March 22, 1 966 0, STQEVER 3,242,279

TIME DELAY MECHANISM Filed Aug. 19, 1965 EXPOSURE DRIVE mo'stoever I V '8 UNIT SYSTEM INVENTOR SHEET I2 msromno (flea/M Fi 9.7 A'rz'oRNsm United States Patent 3,242,279 TIME DELAY MECHANISM Hans 0. Stoever, Rochester, N. assiguor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Filed Aug. 19, 1963, Ser. No. 302,939 6 Claims. (Cl. 200-61.42)

This invention relates generally to sensing mechanisms, and more specifically to a time delay mechanism for starting a document handling apparatus having a treating zone, sensing a document of any length as it is transported past the mechanism, and providing a predetermined time interval following the sensing of the document to enable the document to pass through the treating zone before the mechanism automatically stops the apparatus.

Photographic copying apparatus in which sheets of.

material are passed through a treating zone such as an exposure unit, and at least one of the exposed sheets is introduced into a processing solution in the course of making copies, are well known in the art. In apparatus of this type, it is sometimes advantageous to include a time delay mechanism which will (1) simultaneously turn on the exposure unit and cause the sheet transporting means to operate, (2) sense the sheets of material as they are transported by the sheet transporting means past the mechanism and into the exposure unit, and (3) provide a predetermined time interval following the sensing of the passage of the sheets to enable the sheets to pass through the exposure unit before the mechanism automatically stops the apparatus. As indicated, the purpose of the predetermined time delay in this type of apparatus is to assure operation of the apparatus for a sufiicient time to enable the sheets of material to pass completely through the exposure unit or to reach some other preselected position before it is turned off. Although this illustrates one possible application of applicants time delay mechanism, it should be readily apparent that this mechanism may be useful in any apparatus in which a sheet is fed into a treating zone, and it is desired to proceed with the treatment for a predetermined time before the apparatus is automatically turned off.

It is therefore an object of the present invention to provide a time delay mechanism for an apparatus having a treating zone which will automatically start the apparatus, sense a document as it is transported past the time delay mechanism and into the treating zone, and provide a predetermined time interval following the sensing of the document to enable the document to proceed to a preselected position in the treating zone before the mechanism automatically stops the apparatus.

Another object of the invention is to provide a time delay mechanism for a photographic copying apparatus or the like that is of simple design and construction, thoroughly efiicient and reliable in operation, and economical to manufacture.

Objects and advantages other than those set forth above will be apparent from the following description when read in connection with the accompanying drawings, in which:

FIG. 1 is a schematic front elevation view of a preferred embodiment of the time delay mechanism of this invention in its normal position with a sheet of material about to be fed into the mechanism;

FIG. 2 is a side elevation view of FIG. 1 with the switch and frame omitted and a sheet guiding mechanism added;

FIG. 3 is a view similar to FIG. 1 showing the position of the mechanism as a sheet of material is passed by it;

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FIG. 4 is a side elevation view of FIG. 3 similar to FIG. 2;

FIG. 5 is a view similar to FIGS. 1 and 3 and showing the position of the mechanism after the sheet of material has been transported past the mechanism;

FIG. 6 is a side elevation View of FIG. 5 similar to FIGS. 2 and 4; and

FIG. 7 is a block wiring diagram showing one possible application of the time delay mechanism.

As shown in the drawing, a frame 8 supports a shaft 10 for rotatable and axial movement. The shaft 10 has an arm 12 at one end thereof having a turned end 14 adapted to mesh with a worm 16. The shaft 10 further has a projection 18 intermediate its ends adapted when the arm 12 and worm 16 are enmeshed to extend across the entry throat 20 of a sheet material guiding means 22. The guiding means 22 may be of any well known type for guiding a sheet 23 into an apparatus having a treating zone such as a photographic copying machine. A spring 24 having one end 26 fixed to shaft 10, and its other end 28 bearing on frame 8, encircles shaft 10 and applies to it both a torque which urges arm 12 in a clockwise direction (see FIGS. 2, 4 and 6) towards worm 16, and a lateral thrust which urges shaft 10 in the axial direction indicated by the arrow A in FIG. 1. The axial movement of shaft 10 is limited by an annular shoulder 30 at its opposite end adapted to engage frame 8 as seen in FIGS. 3 and 5. A microswitch 32 which controls the drive system and exposure unit of an apparatus of the type shown in FIG. 7 is located in alignment with shoulder 30 and is responsive to the axial movement of shaft 10. The drive system may be of any well known type for driving worm 14, and any well known sheet transporting means such as opposed rollers or an endless belt trained over a portion of the periphery of a glass cylinder for transporting the sheets of material through the exposure unit, or any other treating zone of an apparatus.

The operation of the time delay mechanism in connection with any apparatus having a treating zone is as follows. Initially, the mechanism is as shown in FIGS. 1 and 2 in which the microswitch 32 is held in an open position by shoulder 30 so that no power is connected to the apparatus. When a sheet 23 of material which may comprise one or more individual sheets is manually pushed through the entry throat 20 into the apparatus, the leading edge thereof engages projection 18 (see FIG. 2) and .pivots the projection 18 and shaft 10 in a counterclockwise direction against the torque of spring 24 from the FIG. 2 position to the FIG. 4 position. As soon as the end 14 of arm 12 is disengaged from worm 16, the spring 24 urges shaft 10 in an axial direction as shown by the arrow A until the shoulder 30 engages frame 8. This axial movement of shaft 10 releases microswitch 32 which moves to its closed position connecting the power supply to the drive system, which drives the worm 16 in the direction indicated by the arrows in FIGS. 4 and 6, and to any other system such as an exposure unit in a photographic copying apparatus. The mechanism is now in the position shown in FIGS. 3 and 4, and remains in this position until the trailing edge of sheet 23, which is being transported by any known sheet transporting means, passes projection 18 releasing it. When this occurs, the spring 24 moves shaft 10 back to its initial angular position causing end 14 of arm 12 to re-engage the driven worm 16. The worm 16 is so threaded that shaft 10 is returned by virtue of the worm 16 and arm 12 connection to its original position against the bias of spring 24. This action continues until shoulder 30 actuates microswitch 32 moving it to its open position disconnecting the power to the apparatus.

The time delay between the time the trailing end of sheet 23 releases projection 18, and the apparatus is stopped is governed by the rate of rotation in revolutions per minute and the pitch of worm 16, and the axial distance that shaft has to be moved.

The invention has been described in detail with particular reference to a preferred embodiment thereof, but it will be understood that variations and modifications can be efliected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

I claim:

1. In a time delay mechanism for an apparatus of the .type having a drivesystem and a sheet treating zone into which a sheet fed into the apparatus is tran'sported by operation of said drive system, the combination comprising:

a member mounted for rotational and axial movement from an initial position;

a drive element driven by a drive system;

means for biasing said member in (1) a rotational direction causing said member to engage said drive element, and (2) an axial direction when said member is disengaged from said drive element by a leading end of a sheet engaging said member and moving said member in the opposite rotational direction as said sheet is fed into the apparatus, said member remaining disengaged from said drive element as long as said sheet remains in engagement with said member; and

control means movable between first and second posi-,

4 means for movement to its first position causing said drive system to drive said drive element to return said member to its initial position after said member is released by said sheet and moves into engagement with said driven drive element, said member as it returns to its initial position moving said control means to its second position to stop said drive system.

2. The invention according to claim 1 and further including a support for said member, and said biasing means comprises a prestressed helical spring having one end secured to said member and its opposite end attached to said support.

3. The invention according to claim 1 and further including a stop means for limiting the axial movement of said member by said biasing means.

4. The invention according to claim 3 wherein said stop means comprises a shoulder on said member cooperating with said support.

5. The invention according to claim 1 wherein said control means comprises an electrical switch.

6. The invention according to claim 1 and further including a support for said member and a stop means for limiting the axial movement of said member by said biasing means, said biasing means comprising a prestressed helical spring having one end secured to said member and its opposite end attached to said support, and said stop means comprising a shoulder on said member cooperating with said support, and said control means comprising a normally closed electrical switch movable from its closed position to its open position by axial movement of said member induced by said drive member.

No references cited.

ROBERT K. SCHAEFER, Acting Primary Examiner. 

1. IN A TIME DELAY MECHANISM FOR AN APPARATUS OF THE TYPE HAVING A DRIVE SYSTEM AND A SHEET TREATING ZONE INTO WHICH A SHEET FED INTO THE APPARATUS IS TRANSPORTED BY OPERATION OF SAID DRIVE SYSTEM, THE COMBINATION COMPRISING: A MEMBER MOUNTED FOR ROTATIONAL AND AXIAL MOVEMENT FROM AN INITIAL POSITION; A DRIVE ELEMENT DRIVEN BY A DRIVE SYSTEM; MEANS FOR BIASING SAID MEMBER IN (1) A ROTATIONAL DIRECTION CAUSING SAID MEMBER TO ENGAGE SAID DRIVE ELEMENT, AND (2) AN AXIAL DIRECTION WHEN SAID MEMBER IS DISENGAGED FROM SAID DRIVE ELEMENT BY A LEADING END OF A SHEET ENGAGING SAID MEMBER AND MOVING SAID MEMBER IN THE OPPOSITE ROTATIONAL DIRECTION AS SAID SHEET IS FED INTO THE APPARATUS, SAID MEMBER REMAINING DISENGAGED FROM SAID DRIVE ELEMENT AS LONG AS SAID SHEET REMAINS IN ENGAGEMENT WITH SAID MEMBER; AND CONTROL MEANS MOVABLE BETWEEN FIRST AND SECOND POSITIONS FOR STARTING AND STOPPING, RESPECTIVELY, SAID DRIVE SYSTEM, SAID CONTROL MEANS BEING RESPONSIVE TO THE AXIAL MOVEMENT OF SAID MEMBER BY SAID BIASING MEANS FOR MOVEMENT TO ITS FIRST POSITION CAUSING SAID DRIVE SYSTEM TO DRIVE SAID DRIVE ELEMENT TO RETURN SAID MEMBER TO ITS INITIAL POSITION AFTER SAID MEMBER IT RELEASED BY SAID SHEET AND MOVES INTO ENGAGEMENT WITH SAID DRIVEN DRIVE ELEMENT, SAID MEMBER AS IT RETURNS TO ITS INITIAL POSITION MOVING SAID CONTROL MEANS TO ITS SECOND POSITION TO STOP SAID DRIVE SYSTEM. 